peters



(No Model.)

J. H. SHAW.

KEY}. I I N0..309,411. v Patented Dec. 16, 1884.

'llNirnn drains Parent tries.

JOHN H. SHAlV, OF NEYV HAVEN, CONNECTICUT, ASSIG-NOR TO SAR-GENT &

CO., OF SAME PLACE.

KEY.

SPECIFICATION forming part of Letters Patent No. 309,411, dated December 16, 1884.

Application filed August 25, 1884. (No model.)

To ctZZ 1071,0722, it IN/11]] concern.-

Be it known that I, JOHN H. SHAW, of New Haven, in the county of New Haven and State of Connecticut, have invented a new Improvement in Door-Keys; and I do hereby declare the following, when taken in connection with accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification,and represent. in-

Figure 1, aside view of the key complete; Fig. 2, the steel blank; Fig. 3, the tube; Fig. l, a vertical section through the bit and stem end, withthe tube applied; Fig. 5, a longitudinal section through the mold, with the tube and blank set therein.

This invention relates to an improvement in that class of door-keys in which the bit, shank, and bow are cut from sheet-steel, and

then the stem and shoulder formed by additional metal applied thereto. In some cases this is cast in molds. In other cases a piece of steel is grooved to slip on over the stem end of the flat steel, and secured by closing or solder. This latter is too expensive an opera tion to be practical. The principal wear upon the stem of a key comes upon the back at the shoulder, and in this class of keys in which the stem is cast upon the blank the cast metal is generally so soft as to quickly wear away.

The object of my invention is to construct the key so as to present a steel or hard-metal I surface, but yet so cheap as to be practical; and it consists in applying to the stem end of the blank a sheet-metal tube corresponding in size substantially to the finished stem, and then placing the bit end of the key in suitable molds, into which metal is poured to fill the tube, form the shoulder, and securely unite the tube with the key, and as more fully hereinafter described.

The blank for the key is cut as seen in Fig. 5 2, the stem end a somewhat narrower than the I. spindle Z) of the key, the bit 0 extending from the stem end and in the same plane. On the back of the stem portion is a notch, d, or any irregularity, there, or at some other point, for the engagement of the cast metal, as hereinafter described.

I construct a tube, 0, (see Fig. 3,) from thin sheet metal, preferably steel, bending the blank into tubular form, and so as to bring the two edges substantially parallel with each other, and distant from each other the thickness of the bit of the key-blank. The tubeis somewhat shorter than the length of the spindle, and so that the end of the blank will protrude through the tube. This tube is set onto the stem end over the bit 0, as seen in Fig. 4. Thus prepared, the key is placed in molds which correspond in shape to the finished bit end of the key, and as seen in Fig.

5. Then metal is poured into the mold, and flows through the tube into the recess f, to form i the shoulder g on the key, fill the tube, and close over the tube end, as at h, Fig. l, the blank being shown in that figure in broken lines. This operation firmly unites the sheet- 7o metal tube with the key, as if an integral part of it, and presents a steel or hard-wearing surface at all points where wear comes upon the stem.

The cost of the tubes is trifling, so that the expense of forming the stem is slightly, if any, more than that of casting the stem upon the blank.

I claim The herein-described improvement in doorkeys, consisting of the flat steel blank having a sheet-metal tube applied to the stem end, the shoulder formed, and the tube filled and united to the blank by cast metal, substantially as described.

JOHN H. SHAW. 

